diff --git a/src/controllers/SpeedTestController.ts b/src/controllers/SpeedTestController.ts
index cbc0f63..59993d7 100644
--- a/src/controllers/SpeedTestController.ts
+++ b/src/controllers/SpeedTestController.ts
@@ -1,7 +1,7 @@
 import type {Server as BunServer, BunRequest} from 'bun';
 import type {BunMethodRoutes} from '../net/http/BunHttpServer';
 import {LoggerFactory} from '@techniker-me/logger';
-import type { ISpeedTestService } from '../interfaces/ISpeedTest';
+import type { ISpeedTestService } from '../core/interfaces/ISpeedTestService';
 
 export class SpeedTestController {
   private readonly _logger = LoggerFactory.getLogger('SpeedTestController');
@@ -39,7 +39,7 @@ export class SpeedTestController {
 
     try {
       const receivedData = new Uint8Array(await request.arrayBuffer());
-      const result = await this._service.validateUpload(requestId, receivedData);
+      const result = await this._service.validateTest(requestId, receivedData);
 
       return new Response(JSON.stringify(result), {
         status: result.valid ? 200 : 400,
@@ -50,10 +50,9 @@ export class SpeedTestController {
       this._logger.error('Error processing speedtest data: [%s]', error);
       
       // Distinguish between user error (404, 400) and server error (500)
-      // Simplification: if message is known (from service), return 400 or 404.
       let status = 500;
       if (error.message === 'Request not found or expired') status = 404;
-      if (error.message.startsWith('Data size mismatch')) status = 400;
+      if (error.message?.startsWith('Data size mismatch')) status = 400;
 
       return new Response(JSON.stringify({error: error.message || 'Failed to process request'}), {status, headers: {'Content-Type': 'application/json'}});
     }
@@ -62,25 +61,29 @@ export class SpeedTestController {
   private async getData(request: BunRequest, _server: BunServer<unknown>): Promise<Response> {
     const url = new URL(request.url);
     const size = parseInt(url.searchParams.get('size') ?? this.defaultSize.toString());
-    const timeout = url.searchParams.get('timeout') ? parseInt(url.searchParams.get('timeout')!) : undefined;
+    const timeout = url.searchParams.get('timeout');
+    
+    const options: Record<string, string> = {};
+    if (timeout) options['timeout'] = timeout;
+    if (url.searchParams.get('hashAlgorithm')) options['hashAlgorithm'] = url.searchParams.get('hashAlgorithm')!;
+    if (url.searchParams.get('hashEncoding')) options['hashEncoding'] = url.searchParams.get('hashEncoding')!;
+    if (url.searchParams.get('chunkSize')) options['chunkSize'] = url.searchParams.get('chunkSize')!;
 
     try {
-      const { session, data } = await this._service.generateTestData(size, { timeout });
-
+      const result = await this._service.initiateTest(size, options);
+      
+      // Convert DataView to Uint8Array for Response
+      const dataArray = new Uint8Array(result.data.buffer, result.data.byteOffset, result.data.byteLength);
+      
       const headers = new Headers();
-      headers.set('Content-Type', 'application/octet-stream');
-      headers.set('Content-Length', session.size.toString());
-      headers.set('Content-Hash', session.hash);
-      headers.set('Content-Hash-Algorithm', session.hashAlgorithm);
-      headers.set('Content-Hash-Encoding', session.hashEncoding);
-      headers.set('Content-Chunk-Size', session.chunkSize.toString());
-      headers.set('X-Request-ID', session.requestId);
+      Object.entries(result.headers).forEach(([key, value]) => {
+        headers.set(key, value);
+      });
 
-      return new Response(data, {status: 200, headers});
+      return new Response(dataArray, {status: 200, headers});
     } catch (error: any) {
       this._logger.error('Error generating data: [%s]', error);
       return new Response(JSON.stringify({error: 'Failed to generate data'}), {status: 500, headers: {'Content-Type': 'application/json'}});
     }
   }
 }
-
diff --git a/src/data/RandomData.ts b/src/data/RandomData.ts
new file mode 100644
index 0000000..3c567ae
--- /dev/null
+++ b/src/data/RandomData.ts
@@ -0,0 +1,34 @@
+import {LoggerFactory} from '@techniker-me/logger';
+import {getRandomValues, createHash} from 'node:crypto';
+
+export class RandomData {
+  private readonly _logger = LoggerFactory.getLogger('RandomData');
+  private readonly _size: number;
+  private readonly _data: Uint8Array;
+  private readonly _dataHashAlgorithm: string;
+  private _dataHash: string;
+
+  constructor(size: number) {
+    this._size = size;
+    this._data = getRandomValues(new Uint8Array(size));
+    this._dataHashAlgorithm = 'sha256';
+    this._dataHash = this.generateDataHash(this._data);
+  }
+
+  get hash(): string {
+    return this._dataHash;
+  }
+
+  get data(): DataView {
+    return new DataView(this._data.buffer);
+  }
+  
+  get dataByteLength(): number {
+    return this._data.byteLength;
+  }
+
+  private generateDataHash(data: Uint8Array): string {
+    return createHash(this._dataHashAlgorithm).update(data).digest('base64');
+  }
+}
+
diff --git a/src/index.ts b/src/index.ts
index 3e51c43..e43a70e 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,11 +1,17 @@
 import HttpServerFactory from './net/http/HttpServerFactory';
 import {HealthCheckApiRoutes} from './health/HealthCheckRoute';
 import HealthCheck from './health/HealthCheck';
-import {SpeedTestApiRoutes} from './api/SpeedTestApiRoutes';
+import {SpeedTestController} from './controllers/SpeedTestController';
+import {SpeedTestService} from './services/SpeedTestService';
+import {InMemoryRequestRepository} from './repositories/InMemoryRequestRepository';
 
 const healthCheck = new HealthCheck();
 const healthCheckRoutes = new HealthCheckApiRoutes(healthCheck);
-const speedTestApiRoutes = new SpeedTestApiRoutes();
+
+// Dependency Injection Composition Root
+const speedTestRepository = new InMemoryRequestRepository();
+const speedTestService = new SpeedTestService(speedTestRepository);
+const speedTestController = new SpeedTestController(speedTestService);
 
 // Frontend serving function - using Bun's super simple static file serving
 const serveFrontend = async (_request: any, _server: any) => new Response(Bun.file('./frontend.html'), {
@@ -18,7 +24,7 @@ const serveFrontend = async (_request: any, _server: any) => new Response(Bun.fi
 const server = HttpServerFactory.createBunHttpServer({
   '/': serveFrontend,
   ...healthCheckRoutes.getGETRoute(),
-  ...speedTestApiRoutes.getRoutes(),
+  ...speedTestController.getRoutes(),
 });
 
 const listenPromise = server.listen(8080);
diff --git a/src/interfaces/ISpeedTestRepository.ts b/src/interfaces/ISpeedTestRepository.ts
index ce8169e..735864a 100644
--- a/src/interfaces/ISpeedTestRepository.ts
+++ b/src/interfaces/ISpeedTestRepository.ts
@@ -1,4 +1,4 @@
-import { SpeedTestSession } from '../models/SpeedTestSession';
+import type { SpeedTestSession } from '../models/SpeedTestSession';
 
 export interface ISpeedTestRepository {
   save(session: SpeedTestSession): void;
diff --git a/src/interfaces/ISpeedTestService.ts b/src/interfaces/ISpeedTestService.ts
index 29b1cb0..20b6b1e 100644
--- a/src/interfaces/ISpeedTestService.ts
+++ b/src/interfaces/ISpeedTestService.ts
@@ -1,4 +1,4 @@
-import { SpeedTestResult } from '../models/SpeedTestResult';
+import type { SpeedTestResult } from '../models/SpeedTestResult';
 
 export interface SpeedTestServiceInitParams {
   size: number;